1. Field of the Invention
This invention relates to a catalyst composition showing a high activity for homopolymerizing or copolymerizing olefins. More particularly, it relates to a catalyst composition and a process for the preparation thereof which catalyst composition provides a highly stereoregular polymer in a high yield when the catalyst composition is used for the polymerization of an .alpha.-olefin having at least 3 carbon atoms, and a process for the polymerization of olefins.
2. Description of the Related Art
Many proposals have been made on the process for the preparation of a catalyst component where a solid catalyst component comprising magnesium, titanium and halogen compounds and an electron donor, (i.e., an internal donor) as indispensable ingredients. In most of these proposals, an organic carboxylic acid ester is used as the electron donor, and there is a problem in that an ester smell is left in the formed polymer unless the ester is removed by washing with an organic solvent or the like means. Moreover, these catalyst components have a poor catalytic activity and provide a low stereospecificity. Methods using specific esters, that is, esters having an ether portion as the electron donor have been proposed as the means for overcoming these defects. For example, there can be mentioned a method using an anisic acid ester (Japanese Unexamined Patent Publication No. 48-18986), a method using a furancarboxylic acid ester (Japanese Unexamined Patent Publication No. 59-129205 and No. 54-136590; U.S. Pat. No. 452,555. U.S. Pat. No. 4,255,280 and U.S. Pat. No. 4,330,650), and a method using 2-ethoxyethyl acetate (Japanese Unexamined Patent Publication No. 61-287908). Even if these esters are used, however, industrially satisfactory performances cannot be obtained with respect to the catalytic activity and stereospecificity, and development of a catalyst having further enhanced performances is desired.